Looking at my garden you might come to the correct conclusion that I like plants. I’m not too concerned about design “do’s and don’ts” because I simply like plants and I’ll locate them wherever there’s space for them.
Fortunately I found space towards the back of one of the borders for one of my favourite flowering shrubs, Diablo Ninebark (Physocarpus opulifolius ‘Diablo’). Like many gardeners I have a “thing” for purple foliage plants and like the Black Lace Sambucus I wrote about two weeks ago this shrub has so many redeeming qualities that it’s hard to keep it out of the garden.
In another example of how plant breeding can take a non-descript shrub from anonymity to superstardom, Physocarpus opulifolius has been transformed in a remarkable way. It’s native to northeastern North America and has long been grown in Europe to provide food and cover for wildlife in conservation areas. It has green foliage, white blooms and a rangy growth habit.
It was in Europe that a single plant amongst acres of plants growing in a nursery field developed purple leaves. A German grower put the plant into production and ‘Diablo’ was born. Physocarpus isn’t anonymous any longer.
‘Diablo’ is an outstanding shrub, with dark purple maple-like leaves. The colour holds well even in the hot summer months, and clusters of bright white flowers form in late spring. These blooms turn to pink, before red seed capsules form later in the fall.
Without pruning ‘Diablo’ can grow up to three metres tall, but you can easily keep it lower by cutting it back hard each spring. It will quickly grow back to about two metres tall by season’s end. When the leaves are off the shrub the beautiful chocolate brown inner bark is revealed as the outer bark exfoliates.
In my garden ‘Diablo’ stands tall towards the back of a larger border. In a happy coincidence (because I have no design sense) it wonderfully frames the pink blossoms of a ‘Bonica’ shrub rose all summer. In fall the leaves of ‘Diablo’ are a beautiful orange-red, perfect for cutting and using in a Halloween display.
With the success of ‘Diablo’ there has been other worthy ninebark introductions. ‘Dart’s Gold’ has bright yellow foliage. A cross between ‘Diablo’ and ‘Dart’s Gold’ produced ‘Coppertina’ with foliage that begins with spectacular copper foliage in the spring which matures to purple.
Another cross between these two parents resulted in ‘Center Glow,’ with bright burgundy-red leaves and a golden-orange base in spring, maturing to dark red in summer.
Finally, there’s ‘Summer Wine.’ My summer wine is usually a cold gewürztraminer or a sauvignon blanc, but this ninebark hybrid is essentially a more compact version of ‘Diablo,’ growing to only 1.5-2 metres tall.
I’ve yet to see it used in this manner in a garden, but Physocarpus would make an excellent deciduous hedge, one which would grow quickly and attract birds in the winter to find cover in its dense branches and to eat the seed capsules.
Like the best garden plants Physocarpus ‘Diablo’ and its offspring have interest in all four seasons. This is one of the trademarks of many of the new flowering shrubs that are available to gardeners now.